The present invention relates to a light signal binary device capable of high speed operation and suitable as a light level detector or light relay in optical fiber transmission.
Conventionally, to convert an analog light signal into an electric signal by the binary method, the analog light signal is converted into an analog electric signal by a photoelectric converter element and the obtained analog electric signal is binary processed by an amplifier circuit having a prescribed positive feedback loop. However, if such method is applied to a light level detector, the delay time of the binary amplifier circuit in addition to the delay time of the photoelectric converter element causes a slow response.
Conventionally, when an input digital light signal of poor waveform is converted into an output light signal of correct square waveform by a light relay, the input light signal is detected by a light receiving element and converted into an electric signal, and then the electric signal is electrically shaped and converted into a light signal by a light emitting element to finally obtain the output light signal. However, even by this method, a complicated electrical circuit is necessary between the light emitting element and the light receiving element. Thus, the delay time of the electrical circuit is added to the delay time of the light emitting element and light receiving element, and the phase delay between the input light signal and output light signal is increased.